JP7619463B2 - Wireless communication system, transmitting device, and receiving device - Google Patents

Description

The present invention relates to a technology for spatially multiplexing transmission of wireless signals using the orbital angular momentum (OAM) of electromagnetic waves.

In recent years, in order to improve transmission capacity, spatial multiplexing transmission technology for wireless signals using OAM has been studied (for example, Non-Patent Document 1). Electromagnetic waves with OAM have equiphase surfaces distributed in a spiral shape along the propagation direction centered on the propagation axis. Electromagnetic waves with different OAM modes propagating in the same direction have orthogonal spatial phase distributions in the direction of the rotation axis, so signals can be multiplexed and transmitted by separating the signals of each OAM mode modulated with different signal sequences at the receiving device.

In a wireless communication system using this OAM multiplexing technology, a uniform circular array antenna (hereinafter referred to as UCA (Uniform Circular Array)) is used, in which multiple antenna elements are arranged at equal intervals in a circle, to generate, combine, and transmit multiple OAM modes, thereby achieving spatial multiplexing transmission of different signal sequences (for example, Non-Patent Document 2). For example, a Butler circuit (Butler matrix circuit) is used to generate and separate signals for multiple OAM modes.

J. Wang et al., "Terabit free-space data transmission employing orbital angular momentum multiplexing," Nature Photonics, Vol.6, pp.488-496, July 2012. Y. Yan et al., "High-capacity millimeter-wave communications with orbital angular momentum multiplexing," Nature Commun., vol.5, p.4876, Sep. 2014.

As described above, transmitting and receiving devices using UCA enable high-capacity communications, but in the future, it is hoped that it will be compatible with cellular systems, particularly for use in access lines.

However, with conventional wireless transmission technology using UCA, in order to separate multiple OAM mode signals without interference between the modes, the transmitting antenna and the receiving antenna must be installed facing each other, and axis alignment is required. This makes it difficult to support multi-directional operation. In addition, accurate axis alignment is difficult, and any axial misalignment between the transmitting antenna and the receiving antenna can cause inter-mode interference, leading to a decrease in transmission capacity.

The present invention has been made in consideration of the above points, and aims to provide a technology that enables multi-directional support and reduction of inter-mode interference in wireless transmission technology using UCA.

According to the disclosed technique, there is provided a wireless communication system including a transmitting device and a receiving device,
the transmitting device includes a plurality of UCAs including a first UCA and a second UCA, the receiving device includes a third UCA,
a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces the third UCA;
The transmitting device transmits a signal to a terminal located in any direction using the second UCA.
A wireless communication system is provided.

According to the disclosed technology, a technology is provided that enables multi-directional support and reduction of inter-mode interference in wireless transmission technology using UCA.

FIG. 13 is a diagram showing an example of phase setting of a UCA for generating an OAM mode signal. 1A and 1B are diagrams illustrating an example of a phase distribution and a signal intensity distribution of an OAM multiplexed signal. 1 is a schematic configuration diagram of a communication system according to an embodiment of the present invention. FIG. 13 is a diagram for explaining an outline of the operation. FIG. 13 is a diagram for explaining an outline of the operation. FIG. 11 is a sequence diagram showing a processing flow. FIG. 11 is a sequence diagram showing a processing flow. FIG. 11 is a sequence diagram showing a processing flow. FIG. 11 is a diagram for explaining an operation example. FIG. 11 is a diagram for explaining an operation example. FIG. 2 is a diagram illustrating a configuration example of a transmitting device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration example of a receiving device according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applicable is not limited to the following embodiment.

(Basic operation example)
First, a basic setting and operation example relating to the UCA used in the transmitting device and the receiving device in this embodiment will be described.

Figure 1 shows an example of phase setting of a UCA for generating an OAM mode signal. The UCA shown in Figure 1 is a UCA consisting of eight antenna elements.

In Fig. 1, the signals of OAM modes 0, 1, 2, 3, ... on the transmitting side are generated by the phase difference of the signals supplied to each antenna element (indicated by ●) of the UCA. In other words, the signal of OAM mode n is generated by setting the phase of the signal supplied to each antenna element so that the phase rotates n times (n x 360 degrees). For example, when the UCA is composed of m = 8 antenna elements as shown in Fig. 1 and a signal of OAM mode n = 2 is generated, a phase difference of 360n/m = 90 degrees counterclockwise is set to each antenna element so that the phase rotates two times as shown in Fig. 1 (3).

Note that a signal with the phase rotation direction reversed to that of an OAM mode n signal is called OAM mode -n. For example, the phase rotation direction of a positive OAM mode signal is counterclockwise, and the phase rotation direction of a negative OAM mode signal is clockwise.

By generating different signal sequences as signals in different OAM modes and transmitting the generated signals simultaneously, wireless communication using spatial multiplexing can be performed. On the transmitting side, signals to be transmitted in each OAM mode may be generated and synthesized in advance, and the synthesized signal for each OAM mode may be transmitted using a single UCA, or multiple UCAs may be used to transmit signals for each OAM mode using different UCAs for each OAM mode. It is also possible to perform OAM-MIMO multiplexing transmission using multiple UCAs.

To separate the OAM multiplexed signal on the receiving side, the phase of each antenna element of the receiving UCA is set to be opposite to the phase of the antenna element on the transmitting side. In addition, to separate the signals of OAM-MIMO multiplexed transmission, MIMO technology such as MIMO equalization is used.

Figure 2 shows an example of the phase distribution and signal intensity distribution of an OAM multiplexed signal. In Figures 2 (1) and (2), the arrows represent the phase distribution of OAM mode 1 and OAM mode 2 signals as viewed from the transmitting side at an end face perpendicular to the propagation direction (propagation orthogonal plane). The arrows start at 0 degrees, the phase changes linearly, and the arrows end at 360 degrees. In other words, an OAM mode n signal propagates while its phase rotates n times (n x 360 degrees) on the propagation orthogonal plane. Note that the arrows of the phase distribution of OAM mode -1 and -2 signals point in opposite directions.

The signal intensity distribution and the position where the signal intensity is maximum differ for each OAM mode. However, the intensity distribution of the same OAM mode with a different sign is the same. Specifically, the higher the OAM mode, the farther the position where the signal intensity is maximum is from the propagation axis (Non-Patent Document 2). Here, the OAM mode with a larger value is called a higher-order mode. For example, a signal in OAM mode 3 is a higher-order mode than signals in OAM mode 0, OAM mode 1, and OAM mode 2.

Figure 2 (3) shows the position where the signal strength is maximum for each OAM mode as a circle. The higher the OAM mode, the farther the position where the signal strength is maximum is from the central axis. Also, the beam diameter of the OAM mode multiplexed signal widens depending on the propagation distance, and the circle showing the position where the signal strength is maximum for each OAM mode becomes larger.

(Overview of the embodiment of the present invention)
As mentioned above, a transmitter and a receiver using UCA can enable large-capacity communication, but it is difficult to support multi-directional communication because the transmitter antenna and the receiver antenna must be installed facing each other in front of each other. Even if they are installed facing each other, inter-mode interference is likely to occur due to axial misalignment between the transmitter and receiver antennas.

In this embodiment, we will explain a technology that enables multi-directional support, reduces inter-mode interference, and enables large-capacity transmission between devices. Below, we will explain in detail the system configuration and an example of operation in this embodiment.

(System Configuration)
Fig. 3 shows a schematic configuration example of a wireless communication system according to the present embodiment. As shown in Fig. 3, the wireless communication system according to the present embodiment includes a transmitting device 100 and a receiving device 200. Also, a UE 300, which is a terminal, exists at an arbitrary location. Note that the UE 300 does not necessarily have to exist.

The transmitting device 100 and the receiving device 200 each have a UCA. In transmitting and receiving desired data, the transmitting device 100 multiplexes and transmits one or more OAM mode signals, and the receiving device 200 receives the signal multiplexed with one or more OAM modes transmitted from the transmitting device 100 and separates the signals of each OAM mode. In addition, both the transmitting device 100 and the receiving device 200 are also capable of MIMO multiplexing transmission. Note that OAM multiplexing transmission and MIMO multiplexing transmission may also be called OAM transmission and MIMO transmission.

UE300 may support MIMO multiplexing transmission and not support OAM multiplexing transmission, or may support OAM multiplexing transmission and not support MIMO multiplexing transmission, or UE300 may support both MIMO multiplexing transmission and OAM multiplexing transmission.

In this embodiment, it is assumed that the transmitting device 100 and the receiving device 200 are both stationary devices (e.g., base stations). However, this assumption is merely an example.

(Operation Overview)
An overview of the operation of the wireless communication system in this embodiment will be described with reference to Fig. 4. The transmitting device 100 has two UCAs (called transmitting UCA1 and transmitting UCA2), and the receiving device 200 has one UCA (called receiving UCA). The transmitting device 100 may have three or more UCAs, one of which faces the receiving UCA. The receiving device 200 may also have two or more UCAs.

In the transmitting device 100, the transmission axis of the transmitting UCA1 and the transmission axis of the transmitting UCA2 are each oriented in a different direction. In addition, the transmitting UCA1 and the receiving UCA are arranged to face each other. Although the transmitting UCA1 and the receiving UCA face each other, precise axial alignment is not required.

In the example shown in Figure 4, the transmitting device 100 transmits a signal to the receiving UCA by OAM transmission using the transmitting UCA1, and performs MIMO transmission using precoding using the transmitting UCA2. It is also possible to perform OAM transmission using the transmitting UCA2.

Regarding the transmission UCA2, the transmitting device 100 adaptively switches between the following two uses (1) and (2).

(1) The transmitting UCA2 is used to communicate via MIMO transmission (or OAM transmission) with a UE300 located at a different location from the receiving UCA.

(2) The signal that arrives at the receiving UCA from the transmitting UCA 2 via a reflected wave, etc., is used to reduce inter-modal interference caused by axial misalignment between the transmitting UCA 1 and the receiving UCA.

Note that (1) and (2) may be performed simultaneously. In addition, in FIG. 4, an image is depicted in which the radio wave from the transmitting UCA 2 is reflected by the ground and the reflected wave reaches the receiving UCA, but using the reflected wave from the ground is just one example. The reflected wave may be a wave reflected from a building or the like.

Also, in FIG. 4 (and the examples described in FIG. 6 and onward), the transmitting device 100 has one transmitting UCA1 and one receiving UCA, but this is just one example. As shown in FIG. 5, the transmitting device 100 and the receiving device 200 may each perform OAM-MIMO multiplex transmission using two or more opposing UCAs. In the example of FIG. 5, the transmitting device 100 has three UCAs, transmitting UCA1, transmitting UCA2, and transmitting UCA3. The receiving device 200 has two UCAs, receiving UCA1 and receiving UCA2. Even when the transmitting device 100 and the receiving device 200 each perform OAM-MIMO multiplex transmission using two or more opposing UCAs, the basic operation is the same as (1) and (2) above and the operation described below.

(Detailed operation example)
A more detailed example of operation based on the configuration in Fig. 4 will be described with reference to Fig. 6 to Fig. 8. Below, a description will be given of a case where the UE 300 is present and a case where the UE 300 is not present.

<When UE 300 exists>
An example of operation when UE 300 is present will be described with reference to the sequence shown in Fig. 6. Note that "UE 300 is present" means, for example, that UE 300 is present in a position where it can receive and appropriately demodulate a signal transmitted from the transmitting UCA 2.

In S101 (step 101), UE 300 makes a connection request to transmitting device 100. In this connection request, UE 300 notifies whether OAM multiplex transmission or MIMO multiplex transmission will be used to receive signals from transmitting device 100.

In S102, the transmitting device 100 uses the transmitting UCA1 to transmit a signal to the receiving UCA of the receiving device 200 by OAM multiplex transmission, and at the same time, uses the transmitting UCA2 to transmit a signal to the UE300 by OAM multiplex transmission or MIMO multiplex transmission in response to a request from the UE300. In this example, it is assumed that the signal transmitted from the transmitting UCA2 reaches the UE300 and also reaches the receiving device 200 due to reflection from the ground, etc.

The transmitting device 100 adds a preamble to the signal transmitted from the transmitting UCA 1, 2 and transmits the signal. The preamble is a fixed pattern signal added to the beginning of the transmission signal (transmission packet), and the receiving side can use the preamble to perform channel estimation, etc. The preamble may also be called a known signal. In this embodiment, multiple orthogonal preambles (orthogonal sequences) are used. The orthogonal preambles are transmitted, for example, for each UCA and for each mode.

In S103, UE 300 receives a signal from transmitting device 100 and performs demodulation. In S104, receiving device 200 performs channel estimation using orthogonal preambles added to each of the transmission signal from transmitting UCA1 and the transmission signal from transmitting UCA2.

In S105, the receiving device 200 uses the channel estimated in S104 to remove (reduce) interference from the transmitting UCA 2 and demodulate the signal from the transmitting UCA 1. Interference removal can be performed using digital signal processing such as MIMO equalization processing, channel equalization processing, and successive interference removal processing.

The sequence shown in FIG. 6 is an example, and other sequences can also be implemented. For example, the operation of the sequence shown in FIG. 7 may be performed.

S111 and S112 in Figure 7 are the same as S101 and S102 in Figure 6. In S113 in Figure 7, UE300 performs channel estimation using the preamble received from the transmitting UCA2, and in S115, feeds back the channel estimation result to the transmitting device 100. Using the received feedback, the transmitting device 100 precodes a signal for UE300 and transmits it from UCA2. In S118, US300 demodulates the signal.

Alternatively, UE 300 may add a preamble to the uplink signal and transmit it, and the transmitting device 100 that receives the uplink signal may perform channel estimation based on the preamble, and the channel estimation result may be used for precoding.

On the other hand, in S114, the receiving device 200 performs channel estimation using the preambles added to the transmission signal from the transmitting UCA1 and the transmission signal from the transmitting UCA2, and feeds back the channel estimation result to the transmitting device 100. The transmitting device 100 uses the feedback for precoding the signal of UCA1.

In S117, the receiving device 200 performs interference removal and in S119, demodulates the signal from the transmitting UCA1.

Through the above operation, the transmitting device 100 can acquire channels between the receiving device 200 and UE 300 and the transmitting device 100, and precoding can be performed that can simultaneously reduce interference to the receiving UCA and achieve connection to the UE 300.

The sequences in Figures 6 to 7 are based on the configuration in Figure 4, but similar sequences can be used to perform processing when the configuration shown in Figure 5 is used. Below, we will explain the sequences in Figures 6 to 7 when the configuration shown in Figure 5 is used. Below, we will mainly explain the parts that differ from what has already been explained.

6, in S101, UE300 makes a connection request to transmitting device 100. In S102, transmitting device 100 transmits signals by OAM-MIMO multiplex transmission to receiving UCA1 and receiving UCA2 of receiving device 200 using transmitting UCA1 and transmitting UCA2, and at the same time, transmits signals to UE300 by OAM multiplex transmission or MIMO multiplex transmission using transmitting UCA3 in response to a request from UE300.

In S103, UE 300 receives a signal from transmitting device 100 and demodulates it. In S104, receiving device 200 performs channel estimation using orthogonal preambles added to the transmission signals from transmitting UCA1 and transmitting UCA2, and the transmission signal from transmitting UCA3.

In S105, the receiving device 200 uses the channel estimated in S104 to remove (reduce) interference from transmitting UCA3 and demodulate the signals from transmitting UCA1 and transmitting UCA2.

The sequence shown in FIG. 6 is an example, and other sequences can also be implemented. For example, the operation of the sequence shown in FIG. 7 may be performed.

S111 and S112 in Figure 7 are the same as S101 and S102 in Figure 6. In S113 in Figure 7, UE300 performs channel estimation using the preamble received from transmitting UCA3, and in S115, feeds back the channel estimation result to transmitting device 100. Using the received feedback, transmitting device 100 precodes a signal for UE300 and transmits it from UCA3. In S118, US300 demodulates the signal.

Meanwhile, in S114, the receiving device 200 performs channel estimation using the preambles added to the transmission signals from the transmitting UCA1 and the transmitting UCA2, and the transmission signal from the transmitting UCA3, and feeds back the channel estimation result to the transmitting device 100. The transmitting device 100 uses the feedback for precoding the signals of UCA1 and UCA2.

In S117, the receiving device 200 performs interference removal, and in S119, demodulates the signals from transmitting UCA1 and transmitting UCA2.

<When UE 300 is not present>
An example of operation when UE 300 is not present will be described with reference to the sequence shown in Fig. 8. In S201, the transmitting device 100 transmits a signal to the receiving device 200 by OAM-MIMO multiplexing transmission using the transmitting UCA1 and the transmitting UCA2. Here too, the transmitting device 100 adds an orthogonal preamble to each signal transmitted from the transmitting UCA1 and the transmitting UCA2 and transmits the signal. The transmitted signal from the transmitting UCA2 is reflected by the ground or the like and reaches the receiving UCA.

In S202, the receiving device 200 performs channel estimation using the orthogonal preambles added to the transmission signals from the transmitting UCAs 1 and 2, and simultaneously calculates the inter-mode interference, and in S203, feeds back the inter-mode interference information to the transmitting device 100.

As an example, when OAM multiplex transmission is performed by transmitting OAM mode 1 and OAM mode 2 multiplexed by the transmitting UCA 1, inter-mode interference occurs due to an axis misalignment between the transmitting UCA 1 and the receiving UCA. Inter-mode interference can cause, for example, a portion of the power of a signal transmitted from the transmitting device 100 in OAM mode 1 to be obtained as the power of an OAM mode 2 signal in the receiving device 200.

The inter-mode interference information may be any information that can be used to perform interference compensation (interference reduction). For example, information on the phase shift from the correct phase (as shown in FIG. 1) as an OAM mode signal may be calculated, and this information may be fed back to the transmitting device 100 as inter-mode interference information.

At S204, the transmitting device 100 generates a compensation signal based on the inter-mode interference information fed back from the receiving device 200, and transmits the compensation signal from the transmitting UCA2 by MIMO multiplexing.

In S205, the receiving device 200 demodulates the compensation signal by MIMO equalization using the channel estimated in S202, and in S206, the receiving device 200 demodulates the signal transmitted from the transmitting UCA1 by OAM multiplex transmission by performing inter-mode interference compensation processing between the transmitting UCA1 and the receiving UCA using the compensation signal.

Note that the above-described method of reducing inter-mode interference using "feedback + compensation signal" is just one example. The receiving device 200 may autonomously perform signal processing for inter-mode interference reduction using a signal from the transmitting UCA2 (i.e., using a signal from a direction different from that of the transmitting UCA1).

The sequence in Figure 8 is based on the configuration in Figure 4, but processing can be performed in a similar sequence even when the configuration shown in Figure 5 is used. Below, we will explain the sequence in Figure 8 when the configuration shown in Figure 5 is used. Below, we will mainly explain the parts that differ from what has already been explained.

At S201, the transmitting device 100 transmits a signal to the receiving device 200 via OAM-MIMO multiplex transmission using transmitting UCA1, transmitting UCA2, and transmitting UCA3.

In S202, the receiving device 200 performs channel estimation using the orthogonal preambles added to the transmission signals from the transmitting UCAs 1, 2, and 3, and simultaneously calculates the inter-mode interference, and in S203, feeds back the inter-mode interference information to the transmitting device 100.

As an example, when OAM-MIMO multiplex transmission is performed by transmitting UCA1 and UCA2 multiplexing and transmitting OAM mode 1 and OAM mode 2, inter-mode interference occurs due to an axis misalignment between transmitting UCA1 and UCA2 and receiving UCA1 and UCA2. Inter-mode interference information for compensating for such inter-mode interference is fed back.

At S204, the transmitting device 100 generates a compensation signal based on the inter-mode interference information fed back from the receiving device 200, and transmits the compensation signal from the transmitting UCA3 by MIMO multiplexing.

In S205, the receiving device 200 demodulates the compensation signal by MIMO equalization using the channel estimated in S202, and in S206, the receiving device 200 demodulates the signals transmitted from the transmitting UCA1 and transmitting UCA2 by OAM-MIMO multiplex transmission by performing cross-mode interference compensation processing between the transmitting UCA1 and transmitting UCA2 and the receiving UCA1 and receiving UCA2 using the compensation signal.

Note that the above-described method of reducing inter-mode interference using "feedback + compensation signal" is just one example. The receiving device 200 may autonomously perform signal processing for reducing inter-mode interference using a signal from the transmitting UCA3 (i.e., using a signal from a direction different from that of the transmitting UCA1 and the transmitting UCA2).

<Summary of operation example>
As shown in Fig. 9, when UE 300 is present, communication with UE 300 is possible by transmitting UCA 2, so communication with UE 300 in any direction is possible. Therefore, multi-directional support can be realized. When the receiving UCA receives a reflected wave of the radio wave from transmitting UCA 2, it can be removed by interference removal processing in receiving device 200.

As shown in FIG. 10, when UE 300 is not present, the signal transmitted from transmitting UCA 2 can be used to reduce inter-mode interference caused by axis misalignment between transmitting UCA 1 and receiving UCA.

The inter-mode interference reduction process shown in FIG. 10 can also be applied when the UE 300 shown in FIG. 9 is present. In other words, the process shown in FIG. 9 and the process shown in FIG. 10 may be combined.

(Device configuration example)
Next, an example of the device configuration of the transmitting device 100 and the receiving device 200 will be described.

<Transmitting device 100>
First, the transmitting device 100 will be described. Fig. 11 is a diagram showing an example of the configuration of the transmitting device 100 in this embodiment. As shown in Fig. 11, the transmitting device 100 has a UCA 110_1, a UCA 110_2, an OAM mode generating unit 120, a signal processing unit 130, and a control unit 140. The UCA 110_1 and the UCA 110_2 correspond to the above-mentioned transmitting UCA 1 and transmitting UCA 2.

The signal processing unit 130 generates a digital signal from the input data to be transmitted on a carrier wave, converts the digital signal to an analog signal (digital-to-analog conversion), and converts the frequency of the analog signal to the frequency band of the carrier wave (e.g., 28 GHz band). The signal processing unit 130 inputs the generated analog signal to the OAM mode generation unit 120.

The OAM mode generation unit 120 generates signals for each OAM mode and supplies the generated signals to UCA 110_1 and UCA 110_2. Note that the OAM mode signals here may be OAM mode 0 signals (general antenna transmission signals).

The OAM mode generating unit 120 is, for example, a Butler circuit. However, generating an OAM signal by analog processing such as a Butler circuit is just one example. The OAM mode signal may be generated by digital signal processing.

The control unit 140 receives a connection request from the UE 300 and instructs the signal processing unit 130 and the OAM mode generation unit 120 to generate a signal (OAM or MIMO) in response to the connection request. The signal processing unit 130 and the OAM mode generation unit 120 generate a signal in accordance with the instruction.

In addition, the control unit 140 receives feedback (inter-mode interference information) from the receiving device 200 and instructs the signal processing unit 130 and the OAM mode generation unit 120 to generate a compensation signal based on the feedback. The signal processing unit 130 and the OAM mode generation unit 120 generate a signal according to the instruction.

<Receiving device 200>
Next, a description will be given of the receiving device 200. Fig. 12 is a diagram showing an example of the configuration of the receiving device 200 in this embodiment. As shown in Fig. 12, the receiving device 200 has a UCA 210, an OAM mode separation unit 220, a signal processing unit 230, and a control unit 240.

UCA 210 corresponds to the receiving UCA described above. OAM mode separation unit 220 has a Butler circuit. Note that using a Butler circuit for OAM mode separation is one example. OAM mode separation may also be performed by digital signal processing.

The signal processing unit 230 converts the analog signal received from the OAM mode separation unit 220 (assuming a Butler circuit) into a digital signal (analog-to-digital conversion), performs demodulation, generates and outputs data (bit string).

In addition, the signal processing unit 230 performs channel estimation, MIMO equalization processing, channel equalization processing, successive interference cancellation processing, calculation of inter-mode interference information, etc. In addition, the signal processing unit 230 can perform both inter-mode interference reduction processing using a compensation signal and inter-mode interference reduction processing without using a compensation signal.

The control unit 240 has the function of issuing operational instructions to the OAM mode separation unit 220 and the signal processing unit 230, as well as the function of transmitting inter-mode interference information calculated by the signal processing unit 230 to the transmitting device 100 as feedback.

(Effects of the embodiment)
The technology according to the present embodiment described above enables multi-directional support in a wireless transmission technology using UCA, and enables inter-mode interference reduction between opposing UCAs. In addition, it is possible to adaptively switch between multi-directional support and inter-mode interference reduction between opposing UCAs. In addition, it is also possible to simultaneously perform multi-directional support and inter-mode interference reduction between opposing UCAs.

(Summary of the embodiment)
This specification describes at least the wireless communication system, the transmitting device, and the receiving device described in the following sections.
(Section 1)
A wireless communication system including a transmitting device and a receiving device,
the transmitting device includes a plurality of UCAs including a first UCA and a second UCA, the receiving device includes a third UCA,
A wireless communication system, wherein a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces the third UCA.
(Section 2)
The wireless communication system according to claim 1, wherein the transmitting device uses the second UCA to transmit a signal to a terminal located in any direction.
(Section 3)
The wireless communication system described in claim 1 or 2, wherein the receiving device utilizes a signal transmitted from the second UCA to reduce inter-mode interference between the first UCA and the third UCA.
(Section 4)
A transmitting device used in a wireless communication system including a transmitting device and a receiving device,
a plurality of UCAs including a first UCA and a second UCA;
A transmitting device, wherein a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces a third UCA provided in the receiving device.
(Section 5)
The transmitting device according to claim 4, further comprising: receiving information on inter-mode interference between the first UCA and the third UCA as feedback from the receiving device; and transmitting a compensation signal for compensating for the inter-mode interference to the receiving device based on the feedback.
(Section 6)
A receiving device for use in a wireless communication system, the receiving device including a transmitting device having a plurality of UCAs including a first UCA and a second UCA,
A receiving device, wherein a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the receiving device further comprises a third UCA opposed to the first UCA.
(Section 7)
The receiving device according to claim 6, wherein a signal transmitted from the second UCA is utilized to reduce inter-mode interference between the first UCA and the third UCA.

Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

100 Transmitting device 110 UCA
120 OAM mode generation unit 130 Signal processing unit 140 Control unit 200 Receiving device 210 UCA
220 OAM mode separation unit 230 Signal processing unit 240 Control unit 300 UE

Claims (4)

A wireless communication system including a transmitting device and a receiving device,
the transmitting device includes a plurality of UCAs including a first UCA and a second UCA, the receiving device includes a third UCA,
a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces the third UCA;
The transmitting device transmits a signal to a terminal located in any direction using the second UCA.
Wireless communication system. A wireless communication system including a transmitting device and a receiving device,
the transmitting device includes a plurality of UCAs including a first UCA and a second UCA, the receiving device includes a third UCA,
a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces the third UCA;
The receiving device utilizes the signal transmitted from the second UCA to reduce inter-mode interference between the first UCA and the third UCA.
Wireless communication system. A transmitting device used in a wireless communication system including a transmitting device and a receiving device,
a plurality of UCAs including a first UCA and a second UCA;
a transmission axis of the first UCA and a transmission axis of the second UCA are oriented in different directions, and the first UCA faces a third UCA provided in the receiving device;
receiving information on inter-mode interference between the first UCA and the third UCA as feedback from the receiving device, and transmitting a compensation signal for compensating for the inter-mode interference to the receiving device based on the feedback;
Transmitting device. A receiving device for use in a wireless communication system, the receiving device including a transmitting device having a plurality of UCAs including a first UCA and a second UCA,
The transmission axis of the first UCA and the transmission axis of the second UCA are oriented in different directions, and a third UCA is provided opposite the first UCA.
A signal transmitted from the second UCA is utilized to reduce inter-mode interference between the first UCA and the third UCA.
Receiving device.

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